<html>
<head> 
<meta charset="utf-8">
<title>属性选择器</title>
<link href="ys.css" rel="stylesheet" type="text/css">
</head> 
<body>
<form action="#">
  <div class="wrapper">
    <div class="box">
      <input type="radio" checked="checked"  id="boy" name="1" /><span></span>
    </div>
    <label for="boy">男</label>
  </div>
  
  <div class="wrapper">
    <div class="box">
      <input type="radio"  id="girl" name="1"  /><span></span>
    </div>
    <label for="girl">女</label>
  </div>
</form> 
</body>
</html>